I Islami; A.A Mehrabi; GH.R Zehtabian; M.R Ekhtesasi; M.A Zare Chahooki
Volume 63, Issue 3 , December 2010, , Pages 287-305
Abstract
Yazd province because of cultural and historical background of the distant past always had known as ambitious and hard-working people. Manifesting multiple efforts of these people is seen in water harvesting. In Yazd province, background issues such as evaluation and assessment of water, ownership and ...
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Yazd province because of cultural and historical background of the distant past always had known as ambitious and hard-working people. Manifesting multiple efforts of these people is seen in water harvesting. In Yazd province, background issues such as evaluation and assessment of water, ownership and agricultural water share refers to the distant past which has been changes over time in type and form. The purpose of this article, meanwhile a short review of management method and operation of water with a focus on Mirab, the evolution of ownership, irrigation circuit changes over time and changes in water price has been paid. Research methodology is single-type reticulum (monographic). Location research has been Chrkhab village of Yazd. Irrigation cycle of village has changed in four stages to the final cycle of water from 16 days to 21 days and 20 hours has become at present. Now, 53 Owner of the well are operating. In this study, according to the classification made, those of their right of water irrigation period were less than one hour (small landowners). This group, forming the highest frequency, equivalent of 33/6 percent was. According to the results, in extent of water right distribution between owners and various whiskers, the owners try to allocate more shares for them in order to play higher roles in the rural society. Study of the current water price changes for fifty years shows, the price of general inflation society has not follow. In this review the current water price increase rate (growth rate), 0/12 percent obtained.
T Mesbahzadeh; H Ahmadi; Gh Zehtabian; F Sarmadian
Volume 63, Issue 3 , December 2010, , Pages 399-415
Abstract
Investigation and preparing of wind erosion intensity maps are the main objectives of this research. In this research, the working unit map was prepared and then nine effective factors in wind erosion according to IRIFR.E.A model are determined at each of seven homogeneous units. According to the results, ...
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Investigation and preparing of wind erosion intensity maps are the main objectives of this research. In this research, the working unit map was prepared and then nine effective factors in wind erosion according to IRIFR.E.A model are determined at each of seven homogeneous units. According to the results, active sand dunes and landuse change showed the highest value with the rate of annual sedimentation more than 6000 ton/km2 while lands surrounding the villages showed the least value with an annual rate of sedimentation of 150-500 ton/km2. Also considering whole area which is about 16161 hectares, around 1978 hectares are classified in low class of desertification; 7430 hectares in medium class while 6753 hectares in high and very high classes.
S. H. Hosseini; S. Feiznia; H. R. Peyrovan; Gh. R. Zehtabian
Volume 62, Issue 2 , October 2009, , Pages 215-228
Abstract
In Iran, fine grained formations (Neogene's units) are very susceptible to erosion. Also, they are the units producing runoff and causing soil loss in watersheds. The objectives of this study is to assess the effect of physical - chemical and mechanical properties of these formations on sediment and ...
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In Iran, fine grained formations (Neogene's units) are very susceptible to erosion. Also, they are the units producing runoff and causing soil loss in watersheds. The objectives of this study is to assess the effect of physical - chemical and mechanical properties of these formations on sediment and runoff rates at different rainfall intensities, based on using field simulator in Taleghan Basin. For this purpose, Neogene's units were separated into five sub-units including Halite siltstone (NgSiH), Siltstone (NgSi), Mudstone (gy1C), Gypsum mudstone (gy1CG) and Halite clay stone (gy2CH), based on physical and chemical properties. Then, runoff and sediment rates were determined in each sub-units at two different intensities (30 and 60 mm/h) using rainfall simulator. Analysis of variance and Duncan's tests showed that NgSiH sub-unit has produced the highest amount of runoff and sediment rates and then the runoff and sediment rates of other subunits in decreasing order are as follows: NgSi, gy2CH, gy1CG and gy1C are 5% significant level. The trend of induced runoff and sediment rates at different times showed that in NgSiH and NgSi sub-units, runoff amounts were fixed rapidly at second ten minutes. Also, on the other sub-units, runoff amounts were fixed at third ten minutes but sediment yield was increased rapidly at third ten minutes.